Rudolph M G, Veit T J, Reinstein J
Max-Planck-Institut für Molekulare Physiologie, Abetilung Physikalische Biochemie, Dormund, Germany.
Protein Sci. 1999 Dec;8(12):2697-704. doi: 10.1110/ps.8.12.2697.
Direct thermodynamic and kinetic investigations of the binding of nucleotides to the nucleoside monophosphate (NMP) site of NMP kinases have not been possible so far because a spectroscopic probe was not available. By coupling a fluorescent N-methylanthraniloyl- (mant) group to the beta-phosphate of CDP via a butyl linker, a CDP analogue [(Pbeta)MABA-CDP] was obtained that still binds specifically to the NMP site of UmpKdicty, because the base and the ribose moieties, which are involved in specific interactions, are not modified. This allows the direct determination of binding constants for its substrates in competition experiments.
到目前为止,由于缺乏合适的光谱探针,无法对核苷酸与NMP激酶的核苷单磷酸(NMP)位点的结合进行直接的热力学和动力学研究。通过经由丁基连接子将荧光N-甲基邻氨基苯甲酰基-(mant)基团连接到CDP的β-磷酸基团上,获得了一种CDP类似物[(Pβ)MABA-CDP],它仍然能特异性地结合到UmpKdicty的NMP位点,因为参与特异性相互作用的碱基和核糖部分未被修饰。这使得在竞争实验中能够直接测定其底物的结合常数。